<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>HTML5</title>
<script type="text/javascript">
function draw(){
	var canvas = document.getElementById('canvas');
	if (canvas.getContext){
		var ctx = canvas.getContext('2d');
		ctx.fillRect(25,25,100,100);
		ctx.clearRect(45,45,60,60);
		ctx.strokeRect(50,50,50,50);
	}
}
</script>
</head>
<body onload="draw();">
	<canvas id="canvas" width="300" height="300"></canvas>
</body>
</html>
